REL and autoimmune disease: Although c-Rel deficiency confers resistance to several T cell–dependent autoimmune disorders such as EAE and collagen-induced arthritis (100, 104), novel data have demonstrated the anti-inflammatory effect of c-Rel in promoting the Treg cell lineage, as revealed in c-Rel–deficient mice, in which thymic and peripheral CD4+ Foxp3+ T cells were vastly reduced in number compared to wild-type counterparts (105, 106).